The present invention relates to fasteners such as nails and the like and, more particularly, to a stack of such fasteners for use in a fastener driving apparatus.
With the advent of fast-acting fastener driving tools, there has come to be appreciated the need for a means of rapidly feeding fasteners into the tool so as to fully utilize the time-saving capabilities thereof.
Prior attempts at automating the feeding of such fasteners have involved adhering the fasteners to paper or similar strips, as seen in U.S. Pat. Nos. 3,212,632 and 3,276,576. Strips of fasteners formed in this manner are seen to suffer several shortcomings. The strips are fragile and prone to breakage, requiring operator intervention before automatic feeding may be resumed. Further, during the driving operation, wherein a fastener is torn from the assemblage, bits of strip and of the adhesive accumulate within the tool where they cause tool malfunction. Other random bits of adhesive and of the strip remain attached to the fastener, preventing complete and proper seating thereof in the receiving material. The remainder of the strip material collects in the work area whereat it constitutes an unwanted litter. Finally, formation of the strips so as to retain both the individual fasteners and the strip integrity, yet to permit the controlled removal of a single fastener by operation of the tool during the fastener driving operation, is both difficult and expensive. In addition, strips suffer from the inability to combine portions of strips to fill a magazine. Operators, coming to a momentary natural pause in their work, frequently use this opportunity to reload the tool with a fresh strip and discard the remaining portion of the previous strip. This practice is, of course, quite wasteful and expensive.
Another problem often encountered is the requirement of a guide washer for proper placement and control of the fastener in the tool barrel during the placement operation. Attempts at forming the strip to fracture at predetermined points, with the portions adjacent the fastener serving as a washer, have generally proven unsuccessful due to the wide variance in size of the washers thus produced.
U.S. Pat. No. 3,276,576 also discloses the use of washers placed on the individual fasteners and adhesively fastened together to form a continuous strip. This method, although solving the litter and guide washer problems, still suffers many of the remaining shortcomings previously described.
The several disadvantages exhibited by the prior art are overcome by the present invention wherein a stack of individual fastening assemblies is provided, each such assembly consisting of a fastener and a washer. The assemblies are arranged such that the bottom fastener of the stack may be fired from the tool without disturbing the remainder of the stack. This stacking is made possible by the novel configuration of the washer, which is generally rectangular and includes two cut-outs or recesses, disposed one each near the midpoints of the top and bottom edges, while a centrally located aperature retainingly grips the shank of the associated fastener. The fastener assemblies are stacked one atop the next, in overlapping relation, with each assembly being rearward of the one below, and the shanks of the fasteners each resting in the upper recess of the washer below. The bottom recess, which is sized to permit passage of the larger of the tool piston and the fastener head, permits the fastener head and the piston to pass through the overlapped portion of the washer of the next-to-bottom fastener assembly, whereby firing may be accomplished without disruption of the remainder of the stack.